According to this invention, there is provided a blind rail having an elongate channel including an elongate inner channel for supporting or retaining blind components and an elongate outer channel having means for mounting of the rail, said inner channel being accommodated within said outer channel.
Also according to this invention, there is provided a blind rail, as defined above, wherein said elongate channel includes:
a base wall extending widthwise in a first direction between first and second base edges;
first and second side walls, extending respectively from said first and second base edges to respectively first and second side edges in a second direction generally perpendicular to said first direction;
first and second inturned flanges extending inwardly from said first and second side edges respectively in generally said first direction so as to define a slot therebetween; and wherein
said base wall, said first and second side walls and at least part of said first and second inturned flanges respectively include an inner base wall, first and second inner side walls and first and second inturned inner flanges of said inner channel.
Further according to this invention, there is provided a method of forming a blind rail as defined above comprising:
roll-forming a first elongate sheet into a cross-section partly conforming to the cross-section of the inner channel;
roll-forming a second elongate sheet into a cross-section partly conforming to the cross-section of the outer channel;
feeding the partly roll-formed inner channel into the partly roll-formed outer channel; and
roll-forming the first and second sheets together to obtain the blind rail.
In this way, the elongate channel of a blind rail can be formed by roll-forming and yet still have the inner cross-section formed independently of the outer cross-section. Internal functional features can be provided without being apparent on the outside of the channel and the external section can be shaped for a pleasing appearance without affecting the functional internal features. An inner channel can be formed from an elongate sheet of preferably metal material. An outer channel can likewise be formed from an elongate sheet of preferably metal material. Also the external section or channel can be shaped for different mounting methods while at the same time having a pleasing appearance. The inner and outer sheets together provide improved strength. Furthermore, they can be made of different materials according to requirements for internal and external features. Indeed, the outer sheet forming the outer channel can be coated for a pleasing appearance, without coating the sheet forming said inner channel.
Preferably, at a position intermediate said first and second base edges and said first and second side edges respectively, the sheet forming the inner channel at least one of the first and second inner side walls is folded back on itself so as to form an inwardly facing support flange extending inwardly in generally said first direction, whereby blind components can be supported or retained by the support flange. In the case of a vertical blind head rail these support flanges can be formed to support slat carriages. In the case of a horizontal blind the support flanges can be formed to accommodate the tilt-supports. In the case of a curtain the flanges can be formed to accommodate the curtain gliders, and in the case of a roller blind, provisions can be made to carry the central shaft.
In this way, internal support provisions can be created by the sheet forming said inner channel, such as for supporting vertical blind carriers, without any effect on the outer appearance of the elongate channel.
Preferably, at least one of said first and second base edges, the sheet forming the outer channel is folded back on itself so as to form a mounting flange extending outwardly in generally said first direction, whereby the mounting flange can be used to mount the head rail adjacent to an architectural opening.
Hence, the sheet forming said outer channel can be folded so as to provide means for connecting to a mounting bracket.
Preferably, the sheets forming a first outer side wall of said outer channel, between the first base edge and the first side edge, is spaced apart from said first inner side wall. Between the first base edge and the first side edge, said first outer side wall can have a generally convex or outwardly curved outer form.
Thus, at parts of the cross-section of the elongate channel, the outer channel can take a different form to the inner channel and leave a space therebetween. Hence, the outer sheet formed into the outer channel can form a pleasing outwardly curved surface, whilst leaving the internal functional channel wall flat.
Preferably, adjacent said mounting flange, the sheet of said outer channel forming said first outer side wall is folded back on itself forming an extension extending in generally upward direction so as to hide or cover said mounting flange.
In this way, the sheet forming said outer channel can conceal features of the inner elongate channel. In particular, where the first base edge is provided with a mounting flange, by folding the outer sheet of the first side wall of said outer channel back on itself forming said extension in generally an upward direction it covers or hides the first base edge, and thus the mounting flange will also be concealed when the blind rail is installed adjacent an architectural opening.
The innermost sections of the inturned flanges defining the slot are formed only from the sheet forming said outer channel, by being folded back on itself so as to overlap on the inside of the sheet forming the inner channel.
In this way, the inner channel is securely fixed within the outer channel and the outer channel provides a complete concealment of the inner channel.
At least one edge of the sheet forming the outer channel can be folded back on itself so as to be sandwiched between the respective sheets forming said outer channel and said inner channel.
This provides a secure fixing and prevents there being any sharp edges within the channel.
The sheet forming said inner channel of at least one of the first and second inturned flanges can include an inwardly facing deflection against which an edge of the sheet forming said outer channel abuts.
In this way, where the sheet forming said outer channel is folded onto the inside of the inturned flanges, it is prevented from sliding relative to the sheet forming said inner channel, since its edge abuts the inwardly facing deflection.
Other aspects, features, and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, taken in conjunction with the drawings and from the appended claims.